Do you mean the bit that flaps the wiper back and forth? It's the windshield wiper motor. You could also mean the windshield wiper control, on the dash, that regulates the air flow to the motor. If you mean a pump, you could mean the air pump thingy that is inside the washer bottle that holds the fluid. It has an air regulator control on the dash too. So you could mean about 6 different things... They all run off air pressure.

Mine says "Air Push" on it. It wasn't the air line that broke, but the plate with the threads in it that the line screws into that broke. Im trying to upload pictures from my phone that shows it, but having trouble.

That link is to my windshield motor picture. I couldn't get it to upload here? It is a blurry picture, but it you look closely to a copper line just to the left of the yellow line. you will see what broke.